The present invention relates to inspection of piping for cracks or flaws, and more particularly to apparatus and methods facilitating visual inspection of the piping used in nuclear power generating operations, and the like.
Piping such as that used in nuclear power generating facilities must be inspected prior to use and periodically thereafter to determine whether any cracks or flaws are present, e.g., at welded locations, which could indicate an actual or potential hazardous condition. Conventional means of performing such inspections have included placing a radioactive material on one side and a photographic film on the other side, both exteriorly of the pipe, and ultrasonic means. In the former, it is necessary that the radiation pass through two layers of the piping material at the location being inspected before reaching the film, and the process must be repeated a number of times in order to obtain a complete scan of 360.degree. at a given pipe location. While ultrasonic means are effective in detecting irregularities in the pipe surface, such irregulatiries may be due to normal conditions within the pipe rather than cracks or other faults in the weld or pipe. A totally acceptable means of direct visual inspection has not been practical. In any case, inspection operations of this type have traditionally been very time-consuming and expensive in order to obtain a reliable determination of the presence of potentially dangerous cracks or other faults in the line.
It is a principal object of the present invention to provide a safe, reliable and relatively fast and inexpensive means of inspecting the interior of piping used in nuclear power generating operations for the presence of cracks and faults.
Another object is to provide apparatus for permitting direct visual inspection of the interior of piping to identify any cracks, including minute cracks not normally visible to the naked eye.
A further object is to provide apparatus including a television camera suitable for transport into and out of piping of a nuclear power plant to permit visual inspection of the interior of the piping from a remote location.
Still another object is to provide a reliable apparatus for transmitting an image of the interior of a pipe surface to a remote television monitor which effectively displays for immediate visual identification substantially all minute cracks or flaws which are present on the entire internal periphery of the pipe at a given location along its length.
Other objects will in part be obvious and will in part appear hereinafter.